Cassava Program

RSA4 - Seed Systems and Harvesting

Increased access to clean seed material

Leader: Imran Malik

Collaborators: Erik Delaquis, Roosevelt Escobar, Laothao Youbee

Partners: CRP-RTB, ACIAR, UQ, NAFRI, GDA, CAVAC, CARDI, AGI, CATAS

RSA-4 provides healthy seed of the more productive cassava varieties, leading to the adoption of new varieties to improve productivity in farmers’ fields.

Cassava seed systems (CSS) include the many ways in which cassava farmers or industries can access, maintain, exchange, produce, and store planting material. Seed systems are often broadly categorized as formal or informal, whereas in reality producers often draw on a mixture of sources, thus blurring these categories to fulfill their needs. Nevertheless, CSS are overwhelmingly informal for most farmers across the world, with few government, NGO, or privately sponsored initiatives to produce good-quality planting material. Interventions aiming at introducing improved germplasm, giving support to a new variety adoption program, maintaining varietal purity, increasing the quality and quantity of planting material, and assuring phytosanitary health are critical for maintaining prosperous cassava-based cropping systems.

In 2020, RSA-4 continued to develop healthy seed from more productive cassava varieties, thus driving the adoption of new varieties and improved productivity in farmers’ fields. Through improved access to clean seed material, together with seed system characterization and modeling, we are helping maintain prosperous cassava-based cropping systems in Southeast Asia and Latin America.

Seed system characterization and modeling

In Southeast Asia, our work on the development of clean seed supply systems to deal with the expanding SLCMV epidemic led to the launch of the “Future Stems” facility, in collaboration with NAFRI in Laos. The Lao government included a target for clean cassava stem multiplication in their draft agricultural strategy to 2030. Once approved by the prime minister, the final strategy will mark a first for any country in the region. To scale multiplication activities, tunnel-based multiplication sites have been established in cooperation with private sector actors in the south and north of the country. A video was produced in the Lao language explaining how to build the tunnels (see video).

Experimental auctions started in 2020, with all 20 village sites aiming to complete the activity in early 2021. Following protocols developed by Cassava Program staff for implementation with root and tuber crops, this research centers around the CRP-RTB “toolbox for working with root, tuber and banana seed systems,” which includes 11 distinct tools as well as a glossary for practitioners. A user guide for the toolbox has been published (Andrade-Piedra et al., 2020), with Cassava Program staff contributing importantly to several tools and guides.

Toolbox for working with root, tuber and banana seed systems

The toolbox was completed and launched in2021 thanks to a global effort to synthesize tools and methods for vegetatively propagated crops like cassava (https://tools4seedsystems.org/), along with a user guide that provides an overview of concepts, step-by-step tool usage explanations, and a description of individual tools and features (Andrade-Piedra et al., 2020). Cassava Program staff contributed significantly to this work, including in the design of the user guide for the experimental auction tool (Delaquis et al., 2021).

Social differentiation in adapting seed systems to the impacts of the pandemic

A short article was published in the journal Food Chain describing application of the concept of social differentiation in adapting seed systems to the impacts of COVID-19 (Delaquis and Almekinders, 2020).

The Future Stems cassava clean seed production facility

Achievements included the official launch of the Future Stems facility in Vientiane (a first in Lao PDR) and the implementation of multiplication tunnels with private sector actors in southern Laos (Khounsub Ltd., Champassak Province). These activities were complemented by the release of several capacity building videos on CMD and establishment of clean seed multiplication systems in Lao PDR.

Rapid multiplication of disease-free cassava planting material

Sustainable rapid multiplication of disease-free cassava planting material established in Lao PDR. The tunnel-based system devised for this purpose accelerates the multiplication rate from mother plants by 6-10x compared to traditional field multiplication and by 100-125x over the course of a season. This greatly lowers the cost of distributing planting stems to farmers and thus facilitates variety dissemination.

Multiplication of available exotic germplasm

The tissue culture laboratory at NAFRI’s Rice Research Centre in Vientiane, Laos, and CARDI in Phnom Penh received five IITA varieties supplied as in-vitro plantlets. Upon arrival, the plantlets underwent in-vitro multiplication, with capacity building support from the Cassava Program, followed by hardening in screenhouse facilities and transfer to the field. These plants are being used for rapid multiplication through the Cassava Program’s tunnel system to obtain an adequate number of plants for testing in multilocation trials during the 2022-2023 season.

Water input for cassava varieties during different growth stages

Cassava varieties are being evaluated for optimum yield under different water availability regimes during the drier period of the growth cycle in both Laos and Vietnam.

RSA-4 Publications

1. Andrade-Piedra JL; Almekinders CJM; McEwan MA; Kilwinger FBM; Mayanja S; Delaquis E; Garrett KA; Omondi AB; Rajendran S; Kumar PL; Thiele G; 2020. User guide to the toolbox for working with root, tuber and banana seed systems. RTB User guide (RTB User Guide No. 2020-1). CGIAR Research Program on Roots, Tubers and Bananas (RTB), Lima, Peru. Doi.org/10.4160/9789290605577 https://tools4seedsystems.org/
2. Delaquis E; Almekinders CJM. 2020. COVID-19, seed security and social differentiation: When it rains, it pours. Food Chain 9:103–106. Doi.org/10.3362/2046-1887.20-00003
3. Delaquis E; Kilwinger FBM; Slavchevska V; Rajendran S; Kikulwe E; Newby JC. 2021. User guide to experimental auctions of vegetatively propagated seed. RTB User Guide. International Potato Center. Doi.org/10.4160/9789290605812 https://www.youtube.com/watch?v=VQ9OPzHBTv8